Helgustadir Iceland Spar Mine

Last Updated: 17th Feb 2008

By Daniel Russell

The Iceland Spar Quarry at Helgustadir, Iceland

by Daniel E Russell

Helgustadir Quarry and Mine in Iceland produced enormous quantities of water-clear cleavages of calcite from the mid-17th Century until the 20th Century. In fact, it is thanks to the prolific output of this locality that “Iceland spar” became the generic term for all transparent cleavages of calcite regardlesss of their source.

Location of Helgustadir Quarry

Located on a mountainside overlooking Reydarfjordur, the largest fjord in eastern Iceland and the main trading hub for the region, Helgustadir Quarry and mine takes its name from a small farm nearby.

In 1668, a geological expedition returned a quantity of transparent calcite found at Helgustadir to Europe. Some of the material was acquired by Rasmus Bartholin, a Danish physician and scientist who observed the well-defined double refraction of the cleavages. A year later in 1669 he would document his observations on “Iceland crystals” in a pamphlet titled Experimenta crystalli Islandici disdiaclastici quibus mira & insolita refractio detegitur, a seminal paper which would start a progression of discoveries and theories that would make major contributions to crystallography and optics during the next three centuries. Helgustadir calcite was soon in demand throughout Europe’s scientific community. While the Danish parliament under Frederick III gave its permission for calcite mining at Helgustadir, no large-scale to recover Iceland spar effort was made for many two centiuries. As Kristjansson (2002) points out “crystals of Iceland spar found their way from Helgustadir to Europe by various routes… freight vessels serving nearby trading posts, fishing boats from abroad (mostly French) after 1815, and travelers including local and foreign scientists. The amounts involved are difficult to estimate, but one expedition from the continent in the 1830s was later claimed to have removed 30 - 40 tonnes of crystals.”

Known to 17th and 18th century mineralogists as “Iceland crystal” and “Iceland crystal spar,” the foreshortened name “Iceland spar” (“spath d'Islande”) appears to have first introduced into the literature by Rene Just Hauy about 1782. It was Hauy who accidently dropped a calcite crystal from the collection of his close friend Citoyen de France de Croisset onto the floor, shattering it. Picking up the fragments, Hauy realized that no matter what sized they were, each displayed exactly the same angles between cleavage faces as the other, and as had every cleavage of Iceland spar he had ever seen. Hauy exclaimed "Tout est trouvé!" (“Everything is discovered!”)He suddenly realized that calcite crystals were composed of a unique “primitive form” which, stacked together like building blocks, generated the incredible diversity of crystal forms shown by the species… and, by extension, similar (but not necessarily identically shaped) building blocks formed the crystals of every mineral species. He also used Iceland spar in his early studies of the electrical charge created in crystals when put under pressure (piezoelectricity).

One of the most important uses for Iceland spar was in Nicol prisms, the most cost-effective (yet not inexpensive) mechanism for creating polarized light available during the 19th Century. The Nicols prism lead to the polarized light microscope and a host of other optical tools like the polariscope and dichroscope.

Helgustadir Mine as it appeared ca. 1900

In 1850, the first efforts to commercially exploit the calcite of Helgustadir were launched. At that time, a local minister named Th. Erlendssen owned three fourths of the title to the site, with the Danish government owning the remaining quarter. T F Thomson, a merchant at the nearby fishing village of Seydisfjord obtained Erlandsson’s permission to work the site for Iceland spar. The calcite was carried overland on horseback then transported by boat to Seydisfjord, then sent to Europe. Thomson was replaced in 1854 by merchant H. H. Svendsen, who leased the property from Erlendssen for 10 rigsdalers a year, and licensed the government’s portion for 5 rigsdalers a year.

He continued mining operations on the site until 1862, in which year Herra Tulinius, at Danish merchant operating at Eskifjord, bought out Erlandssen’s title to the property and for 100 rigsdalers obtained a five-year lease of the Government's share. Eskifjord was an hour and a half ride (a tima and a half) from Helgustadir Quarry. Tulinius was allowed to renew the lease for an additional four years for a mere 5 rigsdalers a year, then the Danish government upped the rent to 100 rigsdalers. The government had grown increasingly concerned that Tulinius was flooding the European market with Iceland spar, which would result in an unacceptable depression in price. Finally, in 1872, the government took control of the Hegustadir quarry, paying Tulinius 16,000 kroner (roughly $3,800) for the property, and terminated all mining activities on the site.

Regretfully, their action was too late in coming. Tulinius had worked the quarry as hard as possible during his last year of operation, amassing an enormous stockpile of Iceland spar. More than three hundred tons of Iceland spar of the “ordinary” type were shipped to England alone, selling for 30 kroner a ton. Merrill notes that circa 1900, Thor E. Tulinius, 16 Slotsholmgade, Copenhagen – presumably successor to Herra Tulinius – was still selling Iceland spar!

The site remained effectively dormant until about 1885, when “an attempt was made to re open it. One man was employed, and after spending about a week in the cave, he succeeded in pumping out the water and extracting a fine block of clear spar, which was sold at a high price in London.” (Hoskyns Abrahall, 1890). He adds that a merchant named Gunnarsson was officially delegated the responsibility of operating Helgustadir Quarry, but that “it is hardly to be expected that the buried treasure will soon see the light. Perhaps too the specimens of the best quality have been already removed.”

Merrill (1910) offers the following description of the quarry as it appeared circa 1880:

The veins of spar are in basalt, and at this spot have been laid bare through the erosive action of a small stream called the " Silfurlakur," the Icelandic name of the spar being "Silfurberg " The quarry opening is on the western side of this brook, and at date of writing was some 72 feet long by 36 feet wide (see Fig. 1 of plate). In the bottom and sides of this opening the calc spar is to be seen in the form of numerous interlocking veins, ramifying through the basalt in every direction and of very irregular length and width, the veins pinching out or opening up very abruptly. In Fig. 2 of plate is shown an area of some 40 square feet of the basaltic wall rock, illustrating this feature of the occurrence. Fig. 3 of the same plate shows the largest and most conspicuous vein, the smaller having been omitted in the sketch. The high cliffs on the north side of the quarry are poorer in calc-spar veins, the largest dipping underneath at an angle of about 40°. A comparatively small proportion of the calc spar as found is fit for optical purposes. That on the immediate surface is, as a rule, lacking in transparency. Many of the masses, owing presumably to the development of incipient fractures along cleavage lines, show internal, iridescent, rainbow hues; such are known locally as "litsteinar" (lightstones). Others are penetrated by fine, tube-like cavities, either empty or filled with clay, and still others contain cavities, sometimes sufficiently large to be visible to the unaided eye, filled with water and a moving bubble. The most desirable material occurs in comparatively small masses embedded in a red-gray clay, filling the vein-like interspaces in the bottom of the pit. The non-transparent variety, always greatly in excess, occurs in cleavable masses and imperfectly developed rhombohedral, sometimes 1 to 2 feet in diameter, associated with stilbite.

Helgustadir Quarry and Mine Circa 1880

Reydarfjord Quarry

During the summer of 1889, Eton College chemist J L Hoskyns-Abrahall visited Helgastadir Quarry. “I had been told by my friend, Mr. Madan {probably George Henry Madan, also of Eton) that the difficulty of obtaining large pieces of clear calcspar for optical purposes had been exciting some curiosity as to the state of the quarry itself, and as the peculiarity of the deposit made it an object of interest.”

As required by custom Hoskyns-Abrahall applied to the local Syslumadhur (the local government factotum) – at the time a man named Jón Asmundazson Johnsen – for permission to examine the quarry.

He described the “working face” of the quarry as “a cavity in the rock about twelve yards by five, and some ten feet high, originally filled almost entirely, but now only lined, with immense crystals, which arc fitted so closely together as to form a compact mass, like a lump of sugar with grains averaging ten inches across.” While he was authorized to collect as many specimens as he wished, he soon discovered that “the permission was not of very much use, there being about five feet of water nearly all over the bottom” of the cave… such specimens as I did get involved doing severe penance in walking barefoot over the sharp crystals.”

Hoskyns-Abrahall described the floor of the cave as “covered with a thin layer of very fine chocolate brown mud, which sticks as tenaciously to one's feet as to the crystals. I had to resort to tooth powder to get the latter clean, though the great heaps of spar which lie on the path side and in front of the mouth of the cave were all washed by the rain till they were as bright and transparent as ice.” He added that, as a result of the quarry’s inactivity, “Tulinius remains the proprietor of the whole of the calcspar that is available for physical work, and naturally sells it at a price that is calculated to make his very moderate stock last for a considerable time. The reason of the inaction of the Icelandic government is not very clear…”

With mining suspended, and Tulinius maintaining a virtual monopoly on existing stockpiles of Iceland spar, the scientific community experienced what Kristjansson (2002) refers to as the “Spar Famine”. As the availability of Iceland spar suited for optical purposes dwindled, even the president of the Royal Academy of Science transmitted an official plea to the Danish government to restart mining at Helgastadir

While quarrying was resumed during the period 1895 to 1912, the results were indifferent. Much of the calcite was of poor quality, and wholly unacceptable for optical use. Some years, in spite of concerted efforts, no Iceland spar was found at all at the quarry. Meanwhile, other sources of Iceland spar from around the world were being brought on line. Localities in Montana (Grey Cliff, in Sweet Grass County), California (such as the Darwin Iceland Spar deposit in Inyo County) and New Mexico (Harding Mine in Taos County) began filling the void. Foreign sources, such as the Kenhardr District in South Africa also produced significant amounts of optical quality Iceland spar.

The death knell for the Iceland spar industry was sounded in 1933, when Edwin Land developed “Polaroid”, a man-made film that replaced Iceland spar for many of its most important purposes as a polarizer.

In 1975, the Helgastadir Quarry was declared an national monument by the Icelandic government.